Fig. 1

Diagnostic evaluation. a and b Composite color fundus photographs of both eyes showing the amelanotic choroidal lesions (arrows) at the posterior pole of the right eye (a) and predominantly nasal superior to the optic disc in the left eye (b). c and d Radiographic imaging. CT scan of the chest (c). Note the large mediastinal mass with pleural spreading. MRI scan of the orbits (d). The arrow marks the choroidal lesion. e and f Histological appearance of the undifferentiated thymic carcinoma (400-fold magnification). The H&E stain (e) shows compact nests of undifferentiated epithelial cells with narrow cytoplasm without evidence of keratinization, large vesicular nuclei and high mitotic rate, separated by broad collagen bands (immunostaining for CD5). The tumor cells show a strong expression of CD5 (f) characteristic for an undifferentiated thymic carcinoma